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<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>类型</title>
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            console.log("自执行函数、、、");

            var string_flg = "true";
            var bool_flg = !!string_flg;
            alert(bool_flg);
            if (string_flg === "false") {
                alert("错误1！");
            }
            if(!bool_flg){
                alert("错误2！");
            }

            var flg = true;
            if(flg){
                alert("正确1！");
            }
        })();
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